diff --git a/docs/door-toggle.rst b/docs/door-toggle.rst
new file mode 100644
index 000000000..319a36b36
--- /dev/null
+++ b/docs/door-toggle.rst
@@ -0,0 +1,35 @@
+Door Toggle
+===========
+
+``door-toggle`` is a DFHack Lua tool that bulk locks or unlocks doors and
+hatches within a rectangular area. It opens a small GUI where you choose a
+mode and then select two corners on the map to apply the action to all targets
+in that rectangle.
+
+Usage
+-----
+
+- ``door-toggle``
+  Opens the GUI and waits for the user to pick two corners.
+- ``door-toggle lock``
+  Opens the GUI with the mode set to lock.
+- ``door-toggle open``
+  Opens the GUI with the mode set to unlock.
+
+Behavior
+--------
+
+- The first click sets the starting corner.
+- Moving the mouse shows a live preview of the rectangle to be processed.
+- The second click applies the action to any doors or hatches within the
+  rectangle on the current z-level.
+- Right-click clears the first corner if already set, or closes the tool if
+  no corner is active.
+
+Notes
+-----
+
+- Locking is implemented by setting the building's ``door_flags.forbidden``
+  to ``true``. Unlocking clears that flag.
+- The tool keeps selection mode active by default so you can perform multiple
+  selections without reopening the UI.
diff --git a/door-toggle.lua b/door-toggle.lua
new file mode 100644
index 000000000..c4af8b6c0
--- /dev/null
+++ b/door-toggle.lua
@@ -0,0 +1,250 @@
+-- door-toggle.lua
+-- DFHack tool: bulk lock/unlock doors and hatches in a selected rectangle
+-- Usage:
+--   door-toggle            -> opens GUI
+--   door-toggle lock       -> preselect lock, start selection
+--   door-toggle open       -> preselect unlock, start selection
+
+local gui = require('gui')
+local guidm = require('gui.dwarfmode')
+local widgets = require('gui.widgets')
+
+-- =============================
+-- Core logic
+-- =============================
+
+local function bounds_from(pos1, pos2)
+    return {
+        x1=math.min(pos1.x, pos2.x),
+        x2=math.max(pos1.x, pos2.x),
+        y1=math.min(pos1.y, pos2.y),
+        y2=math.max(pos1.y, pos2.y),
+        z1=math.min(pos1.z, pos2.z),
+        z2=math.max(pos1.z, pos2.z),
+    }
+end
+
+local function is_pos_in_bounds(pos, b)
+    return pos.x >= b.x1 and pos.x <= b.x2
+       and pos.y >= b.y1 and pos.y <= b.y2
+       and pos.z >= b.z1 and pos.z <= b.z2
+end
+
+local function is_toggle_target(bld)
+    local t = bld:getType()
+    return t == df.building_type.Door or t == df.building_type.Hatch
+end
+
+local function apply_to_doors_in_rect(pos1, pos2, mode)
+    local b = bounds_from(pos1, pos2)
+    local changed = 0
+    local skipped = 0
+
+    for _, bld in ipairs(df.global.world.buildings.all) do
+        if is_toggle_target(bld) then
+            local pos = {x=bld.centerx, y=bld.centery, z=bld.z}
+            if is_pos_in_bounds(pos, b) then
+                if bld.door_flags then
+                    if mode == 'lock' then
+                        bld.door_flags.forbidden = true
+                    else -- mode == 'open'
+                        bld.door_flags.forbidden = false
+                    end
+                end
+                changed = changed + 1
+            else
+                skipped = skipped + 1
+            end
+        end
+    end
+
+    return changed, skipped
+end
+
+local function get_action_text(mark)
+    local str = mark and 'opposite' or 'first'
+    return ('Select the %s corner with the mouse.'):format(str)
+end
+
+-- =============================
+-- Preview overlay
+-- =============================
+
+local to_pen = dfhack.pen.parse
+local SELECTION_PEN = to_pen{
+    tile=dfhack.screen.findGraphicsTile('CURSORS', 1, 2),
+}
+
+-- =============================
+-- Window
+-- =============================
+
+DoorToggleWindow = defclass(DoorToggleWindow, widgets.Window)
+DoorToggleWindow.ATTRS{
+    frame_title='Door Toggle',
+    frame={w=44, h=13, r=2, t=18},
+    resizable=true,
+    autoarrange_subviews=true,
+    autoarrange_gap=1,
+    mode='lock',
+    status_text='',
+    selecting=true,
+    mark=nil,
+    on_cancel=DEFAULT_NIL,
+}
+
+function DoorToggleWindow:init()
+    if self.status_text == '' then
+        self.status_text = 'Select the first corner with the mouse.'
+    end
+    self:addviews{
+        widgets.WrappedLabel{
+            view_id='status',
+            text_to_wrap=function() return self.status_text end,
+        },
+        widgets.CycleHotkeyLabel{
+            view_id='mode',
+            label='Mode:',
+            key='CUSTOM_S',
+            options={
+                {label='Lock', value='lock', pen=COLOR_RED},
+                {label='Unlock', value='open', pen=COLOR_GREEN},
+            },
+            initial_option=(self.mode == 'open') and 2 or 1,
+        },
+        widgets.HotkeyLabel{
+            label='Cancel',
+            key='LEAVESCREEN',
+            on_activate=function()
+                if self.on_cancel then self.on_cancel() end
+            end,
+        },
+        widgets.WrappedLabel{
+            text_to_wrap=function()
+                if not self.selecting then return '' end
+                return get_action_text(self.mark)
+            end,
+            pen=COLOR_LIGHTCYAN,
+        },
+    }
+end
+
+function DoorToggleWindow:onInput(keys)
+    if DoorToggleWindow.super.onInput(self, keys) then return true end
+
+    if keys.LEAVESCREEN then
+        if self.on_cancel then self.on_cancel() end
+        return true
+    end
+
+    if keys._MOUSE_R then
+        if self.mark then
+            self.mark = nil
+            self.status_text = 'Select the first corner with the mouse.'
+            self:updateLayout()
+            return true
+        end
+        if self.on_cancel then self.on_cancel() end
+        return true
+    end
+    self.selecting = true
+
+    local pos = nil
+    if keys._MOUSE_L and not self:getMouseFramePos() then
+        pos = dfhack.gui.getMousePos()
+    end
+    if not pos then return false end
+
+    if self.mark then
+        local mode = self.subviews.mode:getOptionValue()
+        local changed, skipped = apply_to_doors_in_rect(self.mark, pos, mode)
+        self.status_text = string.format(
+            '%s %d doors/hatches.',
+            (mode == 'lock') and 'Locked' or 'Unlocked',
+            changed
+        )
+        self.mark = nil
+        self:updateLayout()
+    else
+        self.mark = pos
+        self.status_text = get_action_text(self.mark)
+        self:updateLayout()
+    end
+
+    return true
+end
+
+-- =============================
+-- Screen
+-- =============================
+
+DoorToggleScreen = defclass(DoorToggleScreen, gui.ZScreen)
+DoorToggleScreen.ATTRS{
+    focus_path='door-toggle',
+    pass_movement_keys=true,
+    pass_mouse_clicks=false,
+    mode='lock',
+    start_selection=false,
+}
+
+function DoorToggleScreen:init()
+    local screen = self
+    self.window = DoorToggleWindow{
+        mode=self.mode,
+        on_cancel=function() screen:dismiss() end,
+    }
+    self:addviews{self.window}
+    if self.start_selection then
+        self.window.selecting = true
+        self.window.status_text = 'Select the first corner with the mouse.'
+        self.window:updateLayout()
+    end
+end
+
+function DoorToggleScreen:onRenderFrame(dc, rect)
+    DoorToggleScreen.super.onRenderFrame(self, dc, rect)
+
+    if not dfhack.screen.inGraphicsMode() and not gui.blink_visible(500) then
+        return
+    end
+
+    if not self.window then return end
+    if not self.window.selecting or not self.window.mark then return end
+    if self.window:getMouseFramePos() then return end
+
+    local mouse_pos = dfhack.gui.getMousePos()
+    if not mouse_pos then return end
+
+    local start_pos = self.window.mark
+    local preview_pos = {x=mouse_pos.x, y=mouse_pos.y, z=start_pos.z}
+    local bounds = bounds_from(start_pos, preview_pos)
+    bounds.z1 = start_pos.z
+    bounds.z2 = start_pos.z
+
+    local function get_overlay_pen(pos)
+        if is_pos_in_bounds(pos, bounds) then
+            return SELECTION_PEN
+        end
+    end
+
+    guidm.renderMapOverlay(get_overlay_pen, bounds)
+end
+
+-- =============================
+-- Entrypoint
+-- =============================
+
+local args = {...}
+
+local function start_gui_with_mode(mode, start_selection)
+    local screen = DoorToggleScreen{mode=mode or 'lock', start_selection=start_selection}
+    dfhack.screen.show(screen)
+end
+
+if #args == 0 then
+    start_gui_with_mode('lock', false)
+elseif args[1] == 'lock' or args[1] == 'open' then
+    start_gui_with_mode(args[1], true)
+else
+    qerror('Usage: door-toggle [lock|open]')
+end